Thousands of migrants who forced their way through Guatemala's northwestern border and flooded onto a bridge leading to Mexico, where riot police battled them back, on Saturday waited at the border in the hope of continuing their journey to the US.

A Guatemala City court ruled on Wednesday that the crime of genocide had been perpetrated during the darkest hours of the country’s long civil war, but acquitted a former military intelligence chief of the killings.

Guatemala’s constitutional court on Sunday made a provisional ruling by a unanimous vote to allow the chief of a United Nations-backed anti-graft body to return to the country, a judge told a news conference at the court.

Guatemala’s attorney general and the UN-backed International Commission Against Impunity in Guatemala (CICIG) moved on Friday to lift President Jimmy Morales’ immunity so he can be investigated for alleged illicit campaign financing.

Explosions boomed from Guatemala's fearsome Fuego volcano Wednesday, unleashing fresh torrents of molten mud and ash down slopes where officials said 75 people had been killed and 200 were still missing.

At least 22 girls have been killed in a fire at a government-run home for abused teens, which broke out when residents set mattresses ablaze after an overnight riot and attempt to escape from the overcrowded government-run center.

Homemaker Dulce del Carmen Lavarenzo Pu had just returned from church when the ground shook and she heard a terrible noise. A wave of mudslide from the nearby mountainside and buried everything just 150 feet (50 meters) from her house.

Guatemala's Congress swore in a new president as disgraced former leader Otto Perez was ordered detained to prevent him becoming a fugitive from justice in the Central American nation's long-running corruption saga.